Machine Design Questions and Answers – Viscosity

This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Viscosity”.

1. Viscosity is defined as the external resistance offered by a fluid to change its shape or relative motion of its parts.
a) Yes
b) It is internal resisting force
c) It is not offered but exerted on the fluids
d) None of the listed
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2. Stream line flow happens when intermediate layers move with velocities proportional to the square of distance from the stationary plate.
a) True
b) False
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3. Newton law of viscosity states that shear stress is proportional to rate of shear at any point in the fluid.
a) True
b) False
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4. Calculate the kinematic viscosity if Saybolt viscosity is 400cSt.
a) 400SUS
b) 40.25SUS
c) 86.32SUS
d) 87.55SUS
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5. Viscosity of lubricating oil decrease with increasing temperature.
a) Yes
b) It increases linearly
c) It increases hyperbolically
d) it remains constant
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6. Which of the following lubricant has least rate of change of viscosity w.r.t temperature.
a) VI=20
b) VI=30
c) VI=40
d) VI=50
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7. Which of the following are not true for petroff’s equation?
a) Shaft is considered concentric with the bearing
b) Bearing is subjected to light load
c) Is used to find coefficient of friction
d) Frictional torque is given by fpr²l
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8. In hydrodynamic lubrication, film thickness remains unaffected by change in speeds.
a) True
b) Increase with increase in speed
c) Decrease with increase in speed
d) Disappear as the speed tends to infinty
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9. For a hydrostatic thrust bearing,
Thrust load=450kN, shaft speed=730rpm, shaft diameter=450mm, recess diameter=310mm, film thickness=0.15mm, viscosity of lubricant=160SUS and specific gravity=0.86.
Calculate supply pressure
a) 10.2Pa
b) 4.01Pa
c) 4.01Mpa
d) 10.2Mpa
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10. For a hydrostatic thrust bearing,
Thrust load=450kN, shaft speed=730rpm, shaft diameter=450mm, recess diameter=310mm, film thickness=0.15mm, viscosity of lubricant=160SUS and specific gravity=0.86.
Calculate flow requirement
a) 0.89l/s
b) 38.94l/min
c) 28.8l/min
d) None of the mentioned
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11. For a hydrostatic thrust bearing,
Thrust load=450kN, shaft speed=730rpm, shaft diameter=450mm, recess diameter=310mm,film thickness=0.15mm,viscosity of lubricant=160SUS and specific gravity=0.86.
Calculate power loss in pumping.
a) 2.68kW
b) 3.35kW
c) 2.6kW
d) 4.2kW
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12. For a hydrostatic thrust bearing, Thrust load=450kN, shaft speed=730rpm, shaft diameter=450mm, recess diameter=310mm,film thickness=0.15mm,viscosity of lubricant=160SUS and specific gravity=0.86.
Calculate frictional power loss.
a) None of the listed
b) 2.3kW
c) 3.56kW
d) 4.2kW
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Sanfoundry Global Education & Learning Series – Machine Design.
To practice all areas of Machine Design, here is complete set of 1000+ Multiple Choice Questions and Answers.

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